业务挑战

在当今激烈的市场竞争中，测试覆盖率对许多应用程序是至关重要的。为维持所需的测试覆盖率，设计过程中，执行功能性ECO任务添加或删除寄存器时，则必须更新相关的扫描链和测试模式。

技术挑战

设计过程中，由于扫描链逻辑是由EDA工具自动生成，为了避免任何DFT覆盖率的损失，设计师通常需花费大量的精力处理扫描链的变更。

解决方案的优势

1、缩短设计周转时间

     • 自动更新ECO网表的相关扫描链，确保满足各种DFT约束，大大加快ECO周转速度

     • 基于先进的物理感知逻辑优化算法，利用现有网表和备用单元提供的物理信息，减小路径延迟

2、即插即用，降低第三方设计流程集成难度

     • 包含接口特性，设计师在使用第三方逻辑功能变更解决方案时，可以利用其强大的扫描链修复功能

     • 接口利用了标准数据格式和TCL命令，从而降低流程集成的难度

3、工具易于使用，优化补丁以获取最佳扫描链结果

     •  EasylogicECO提供高度自动化的流程，工具易于使用

     • 基于模板的批量处理模式指导用户完成ECO过程，无需大量的人工干预，便可获取高效、准确的结果

SDFF selection and conversion 

Converts regular DFFs into appropriate SDFFs that need to be inserted into the scan chain.

Scan chain stitching, removal and balancing 

Stitches SDFFs into the original scan chain while disconnecting unnecessary SDFFs.  Customizes the chain length based on user’s DFT constraints to meet the requirements of the test plan, enabling increased test coverage without compromising testing costs.

Support for advanced design requirements 

Ensures compliance with design rules while implementing scan chain revisions.  Identifies multi-clock domains, multi-power domains, and hold time violations and applies necessary adjustments, such as isolation/level shifter cells or lockup latches.

Physical-aware ECO algorithm

Utilizes physical information provided in the LEF/DEF format to enhance timing of the scan chain.

Multiple types of post-mask ECO resource

Resource options for a post-mask ECO task include spare cells, gate arrays, and filler cells.  When combined with physical information, optimizes the delay of scan chains by considering cell function and estimated wire delay.

Versatile design flow support

Supports various ECO flows for introducing changes of FFs, including 3rd-party ECO flow, manual ECO flow, and EasylogicECO flow. It utilizes standard formats for input/output data, enabling seamless integration with mainstream design flow.

Command line script operations

Script-based operation is simple, easy to learn and debug.  It only requires modifying specific script fields when migrating to other projects.